Folding pocket knife with a lock

ABSTRACT

Knives ( 10, 182 ) each include a handle ( 12, 184 ) having a blade ( 14, 90, 194 ) pivotally attached to the handle. The blade is movable between a closed position in which it is received within a groove ( 36, 192 ) of the handle and an open position. The blade has a working portion ( 38, 198 ) and a tang portion ( 44, 98, 204 ), which remains within the groove when the blade is in its open position. A locking pin ( 72, 208 ) extends transversely of the handle and blade and is movable along a pair of elongated openings ( 74, 216 ), and engages the tang portion ( 44, 98, 204 ) of the blade to lock the blade in its open position. A spring ( 78, 228 ) biases the locking pin toward the tang.

This application is a 371 of PCT/US98/07509 filed Apr. 14, 1998 which isa continuation-in-part of Ser. No. 08/679,122 Jul. 12, 1996 now U.S.Pat. No. 5,737,841.

TECHNICAL FIELD

This invention relates generally to folding tools, and more particularlyto a folding tool including blades or tools capable of being locked inan open position.

BACKGROUND ART

Folding knives and tools suitable for many purposes are well known inthe art. For example, U.S. Pat. No. 1,030,058 to Doles, U.S. Pat. No.1,189,005 to Seely, U.S. Pat. No. 2,188,762 to Schrade, U.S. Pat. No.3,868,774 to Miori, U.S. Pat. No. 4,233,737 to Peohlmann, U.S. Pat. No.4,240,201 to Sawby et al., U.S. Pat. No. 4,274,200 to Coder, U.S. Pat.No. 4,451,982 to Collins, U.S. Pat. No. 4,502,221 to Pittman, U.S. Pat.No. 4,670,984 to Rickard, U.S. Pat. No. 4,837,932 to Elsener, U.S. Pat.No. 4,896,424 to Walker, U.S. Pat. No. 5,060,379 to Neely, U.S. Pat. No.5,425,175 to Rogers, and U.S. Pat. No. 5,461,786 to Miller arerepresentative of the available prior art.

As disclosed in several of the aforementioned patents, there are manydifferent mechanisms for locking tool blades in an open position. Forexample, the patents to Sawby et al., Miller and Seely each disclose avariation of a “lock back” mechanism. This construction entails forminga notch on a tang of the blade which is engaged by a lug located on thespine of the knife to lock the blade in an open position. A shortcomingof this type of mechanism is that excessive wear can cause the lockingmechanism to fail, thereby rendering the knife unsafe for use.

The patents to Neely and Collins each disclose another type of lockingmechanism. As disclosed in these patents, a blade has a tang that isengaged by a member to prevent the blade from rotating from its openposition. For example, in Collins, a slidable bolt is biased towards thetang to lock the blade in its open position. A shortcoming withCollins's knife construction is that the bolt is generally parallel withthe blade, and the mechanism depends on the spine of the handle forstrength. Neely's knife suffers from the same disadvantage as Collins's,and from the fact that the blade may be unlocked inadvertently bypulling the blade axially away from the handle during a normal cuttingmotion of the knife.

What is needed, then, is a stronger lock mechanism than has previouslybeen available for holding a blade of a folding tool in an open, orextended, position, yet which is capable of being manufactured at areasonable cost.

DISCLOSURE OF THE INVENTION

The present invention overcomes the above-mentioned shortcomings of theprior art by providing a folding tool comprising an elongate handledefining an elongate groove therein and at least one knife or other toolblade or other tool element pivotally attached to the handle at one end.Each tool blade or element is movable, between a closed position inwhich it is received within the groove of the handle and an openposition in which the blade or tool element is extended away from thehandle and exposed. Each tool blade has a working portion that extendsaway from the handle when in its open position and a tang portionincluding a locking surface which is located within the groove of thehandle when the blade is in its open position. A blade locking pinextends in a direction generally transverse to the length of the handleand blade and has its opposite ends disposed in elongate openingsdefined in opposite sides of the handle and aligned opposite each other.The blade locking pin is movable with respect to the handle along theelongate openings, between a first position, in which the locking pinengages a locking surface of the tang portion of blade as well asinterior surfaces of the elongate openings, to lock the blade in itsopen position, and a second position in which the pin is spaced awayfrom the locking surface portion of the tang to allow the blade to movefrom its open position. The blade locking pin is biased toward its firstposition, but is movable manually to its second position from its firstposition.

In one embodiment of the invention a locking assembly body is providedto move the locking pin manually from its first position to its secondposition.

In one embodiment of the invention the blade locking pin is biasedtoward its first position by a spring housed in a cavity defined withina side wall of the handle.

In one embodiment of the invention a spine portion of the handle islocated adjacent the elongate openings in which the ends of the bladelocking pin are located, and respective parts of an outer surface of theblade locking pin rest against the locking surface on the tang of thetool blade and a surface of the spine.

In one embodiment the invention provides for such locking of selectedone of a plurality of tool blades or elements carried at one end of ahandle.

The foregoing and other-objectives, features, and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of the invention, taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of a folding or pocket knife embodying thepresent invention, a blade of the knife being shown in a closed positionin which it is received within a handle of the knife.

FIG. 2 is a perspective view of the knife shown in FIG. 1, with theblade of the knife shown in an open, operating position.

FIG. 3 is an exploded perspective view of the knife shown in FIG. 2.

FIG. 4 is a partially cutaway elevational view from one side of theknife shown in FIGS. 1-3.

FIG. 5 is a partially cutaway elevational view from the other side ofthe knife shown in FIGS. 1-4.

FIG. 6 is a partially cutaway elevational view of the knife from thesame side as in FIG. 4, the blade being illustrated in its openposition.

FIG. 6a is a detail view of the locking mechanism of the knife as shownin FIG. 6, at an enlarged scale.

FIG. 7 is a partially cutaway elevational view of the knife, similar toFIG. 6, but with the blade of the knife moved toward its closedposition.

FIG. 7a is a detail view of the locking mechanism of the knife as shownin FIG. 7, at an enlarged scale.

FIG. 8 is a side elevational view of a blade for incorporation in aknife that is another preferred embodiment of the invention.

FIG. 9 is a perspective view of a tool handle, pliers jaws, and one toolblade of a multi-purpose tool incorporating a blade lock embodying thepresent invention.

FIG. 10 is a perspective view of a blade pivot shaft and a portion ofthe locking mechanism of the tool shown in FIG. 9, at an enlarged scale.

FIG. 11 is a partially cutaway elevational view of a portion of thehandle and the blade and locking mechanism shown in FIGS. 9 and 10.

FIG. 12 is a partially cutaway elevational view of a portion of thehandle and the blade and locking mechanism shown in FIGS. 9, 10 and 11with the blade in its closed position.

FIG. 13 is a plan view taken from the open or front, side of the toolhandle shown in FIG. 9, together with several tool blades and the bladelocking mechanism shown in FIGS. 9, 10, 11 and 12.

FIG. 14 is an exploded perspective view of a folding knife which isanother embodiment of the present invention.

FIG. 15 is a partially cutaway side elevational view of the knife shownin FIG. 14, with its blade locked in an open position.

FIG. 16 is a partially cutaway side elevational view of the foldingknife of FIG. 14, with its blade locked in its open position, at anenlarged scale.

FIG. 17 is a view similar to FIG. 16 with the blade of the knife locatedonly slightly outward from its closed position.

BEST MODES FOR CARRYING OUT THE INVENTION

Referring now to the drawings, and more particularly to FIGS. 1 and 2, afolding pocket knife 10 includes a blade locking mechanism that embodiesthe present invention. The pocket knife 10 includes an elongate handle12, and a blade 14 that is pivotally attached to the handle at one ofits opposite ends. FIG. 1 shows the pocket knife 10 with the blade 14 ina closed position in which the blade is received within the handle 12.FIG. 2 illustrates the pocket knife 10 with the blade 14 in an open oruse position. The blade 14 of the pocket knife 10 of the presentinvention is capable of being locked securely in that open position toprevent the inadvertent movement of the blade to its closed position,and this ability makes the knife safer to use.

Referring now to FIGS. 1-3, the handle 12 of the pocket knife 10comprises several components, including a pair of oppositely locatedside wall sections, generally indicated at 16, 18, that are parallelwith each other, and a spine section 20 which is located between theside wall sections along their upper long edges. As shown in FIG. 3, theside wall section 16 has an outer plate 22 and an inner liner 24,disposed inwardly alongside the outer plate 22. Similarly, the otherside wall section 18 has an outer plate 26 and an inner liner 28 alsodisposed inwardly alongside its outer plate 26.

When the handle 12 is assembled, the spine section 20 is disposedbetween the liners 24, 28 of the side wall sections 16, 18,respectively, and extends along the upper edge margins of the side wallsections, outwardly projecting detents 30 provided on the spine sectionare received in corresponding bores 32 formed in the liners, to alignthe side wall sections with each other and the spine section. Suitablefasteners such as screws 34 and 35 are used to hold together the sidewall sections 16, 18 and the spine section 20. Preferably, the outerplates 22, 26 of the side wall sections 16, 18, respectively, arefabricated from a reinforced hard synthetic plastics material such asMicarta® (by Westinghouse Electric & Manufacturing Company), althoughother suitable materials such as metal, other plastics, wood, etc. canalso be used. The liners 24, 28 of the side wall sections 16, 18, andthe spine section 20, are preferably fabricated from steel or titaniumsince these components of the handle must be strong enough to bear theforces that might be exerted thereon when locking the blade in its openposition.

The side wall sections 16, 18 and the spine section 20 define a bladereceiving groove 36 (see FIG. 4) for receiving the blade 14 when it ismoved to its closed position. Still referring to FIGS. 1-3, the blade 14comprises an elongate working portion 38 having an upper blunt edge orback 40, a lower sharp edge 42, and a tang portion 44 which pivotallyattaches the blade to the handle 12. The arrangement is such that theblade's working portion 38 extends away from the handle when the blade14 is in its open position, and the tang portion 44 is located withinthe groove 36 when the blade is in either the open or the closedposition. That is, the tang portion 44 is always located between theliners 24 and 28 of the handle 12.

More specifically, the working portion 38 is constructed in a well-knownmanner and is pivotally attached to the handle by the tang portion 44 sothat the lower sharp edge 42 is received within the handle 12. The tangportion 44 is formed integrally with the blade portion 38 and has asemi-circularly-shaped peripheral edge 46, and a circular opening 48 isformed in the tang for attaching the blade 14 to the handle 12. One ofthe ends of the peripheral edge 46 of the tang portion 44 merges into anoutwardly extending first shoulder 50. The other end of the peripheraledge 46 merges into an inwardly extending second shoulder 52. The firstand second shoulders 50, 52 are generally perpendicular with thedirection of the peripheral edge 46 at their respective junctions;however, it should be observed as in FIG. 4 that the second shoulder 52merges into the peripheral edge 46 with a greater radius of curvaturethan does the first shoulder 50.

As shown in FIG. 3, an annular shaft 54 fabricated from hard steelattaches the blade 14 to the handle 12 with one of a pair of annularshims 56 on each side, between the liners 22 and 28. The shaft 54 ispress-fitted into the opening 48 formed in the tang portion 44 of theblade 14 and fits rotatably but snugly through circular openings 57defined in the liners 22 and 28 so that the shaft defines a pivot axisfor the blade extending transversely with respect to the side walls 16and 18. The annular shims 56 are received over respective ends of theshaft 54 as indicated in FIG. 3. The shaft 54 has a threaded axial bore58 machined therethrough for matingly receiving the screw fasteners 34which retain the outer plates 22 and 26 and keep the pocket knife 10assembled.

Referring now to FIGS. 3-5, there is generally indicated at 60 a slidinglock assembly for locking the blade 14 in its open position. The slidinglock assembly 60 includes a planar sliding body member 62 which extendsalong a plane generally parallel with the plane of the side wallsections 16, 18 of the handle 12. Mounted on the body member 62 is anoutwardly projecting latch operating arm member or knob 64 useful as ahandle for slidably moving the body member 62 along an axis generallyparallel with the length of the handle 12 as indicated by the arrow 65in FIG. 3. The body member 62 is disposed between the outer plate 22 andliner 24 of the side wall section 16 in a cavity (not shown) formed inthe inwardly-facing side of the outer plate 22. The body member 62 has afork or slot 66 formed therein which receives a guide member 68 (e.g., amachine screw) suitably attached to the liner 24 to guide the movementof the sliding body member 62. The knob 64 extends outwardly through anelongated opening 70 formed through the plate 22 of the side wallsection 16 so that it is accessible to the user of the pocket knife 10.

The sliding lock assembly 60 further includes a cylindrical bladelocking pin 72 of which one end is attached (e.g., welded) to the bodymember 62. The pin 72 has a cylindrical outer surface 73, and a centralaxis that extends in a generally transverse direction with respect tothe body member and handle 12. When the folding knife 10 is assembled,the pin 72 extends through aligned elongate openings 74 formed in theliners 24, 28 of the side wall sections 16, 18, respectively, and thefree end of the pin 72 extends into a large cavity 76 formed in theinwardly facing surface of plate 26 of side wall member 18. An inwardlyfacing surface 77 of the spine 20 is preferably aligned with or nearlyaligned with the elongate openings 74, as may be seen best in FIG. 7a.As shown in FIG. 4, the pin 72 of the sliding lock assembly 60 islocated adjacent the tang portion 44 of the blade 14.

Turning now in FIGS. 6 and 7, the sliding lock assembly 60 is movable ina direction parallel to the length of the handle 12, as indicated by thearrow 65, between a first position shown in FIG. 6, in which thecylindrical outer surface 73 of blade locking pin 72 of the sliding lockassembly engages the tang portion 44 of the blade 14 to lock the bladein its open position, and a second position, shown in FIG. 7, in whichthe pin 72 is spaced away from the tang portion 44 to allow the blade tomove from its open position and toward its closed position. Morespecifically, when the sliding lock assembly 60 is in its first positionfor locking the blade 14 in its open position, the pin 72 is disposed inrecess defined by the tang portion 44, the first shoulder 50, and spinesection 20. As may be seen best in FIG. 7a, a generally flat lockingsurface 89 is part of the peripheral edge 46 of the tang 44,intersecting and preferably faired into the semicircular portion throughthe transition 88. The locking surface 89 extends inwardly along a chordof the circle defined by the semi-circular portion of the peripheraledge 46. At angle 75, shown in FIG. 6a, is defined between the lockingsurface 89 of the tang 44 and the upper inner surfaces defining theelongate holes 74. The angle 75 is between 7 degrees and 14 degrees andis preferably 10 degrees, and thus is small enough that the pin 72 isnot urged longitudinally away from its first position by any cam actionof the locking surface portion 89 of tang 44 with sufficient force toovercome the force of the spring 78. The arrangement is such that uponan attempt to move the blade 14 from its open position, the pin 72engages the locking surface 89 portion of the peripheral edge 46 of thetang portion 44 of the blade and interferes with the pivotal movement ofthe tang portion, thus preventing movement of the blade 14 about thepivot axis defined by the shaft 54.

Additionally, it should be observed that the pin 72 of the sliding lockassembly 60 has a tendency of “wearing in” rather than wearing out,since the more frequently the blade 14 is moved to its open position andlocked therein by the pin, the further the pin becomes wedged betweenthe peripheral edge 46 of the tang portion 44, the surfaces defining theelongate openings 74 in the liners 22 and 28, and (depending uponalignment) the inner surface 77 of the spine 20.

A spring 78 is provided for biasing the pin 72 of the sliding lockassembly 60 to its first position. As illustrated in FIG. 5, one end 80of the spring 78 engages a detent 82 (e.g., a machine screw) provided onthe liner 28 of the side wall section 18. The other end 84 of the spring78 engages the free end of the pin 72. More specifically, acircumferential groove 86 is formed in the pin 72 near its free end toreceive the end 84 of the spring 78 therein and ensure that the springmaintains its engagement with the pin 72. Preferably, the spring 78 isfabricated from resilient material which is strong enough for biasingthe sliding lock assembly 60 to its first position, but resilient enoughso that when a person applies a force on the knob 64 in a direction awayfrom the extended blade 14, the lock assembly 60 is moved readily to itssecond position.

It should be observed that the peripheral edge 46 of the tang portion 44defines a cam upon which the pin 72 can ride as the blade 14 is movedbetween its open and closed positions. Moreover, referring briefly toFIG. 4, when the blade 14 in its closed position the pin 72 is disposedbetween the peripheral edge 46 of the tang portion 44 and the secondshoulder 52, and upon movement of the blade 14 away from its closedposition the second shoulder moves the sliding lock assembly 60,including the pin 72, to its second position, enabling the blade 14 toopen. It should also be noted that the tang portion 44 of the blade 14can be configured so that the blade is locked in its closed position andcapable of being moved only upon moving the sliding lock assembly 60manually to its second position.

Another important feature of the tang portion of the blade 14 is thatthe shape of the peripheral edge 46 which defines the cam upon which thepin 72 rides can provide an “assist” when opening or closing the blade14 of the knife 10. More specifically, as illustrated in FIGS. 5 and 6,the arrangement is such that during closing of the blade 14 of the knife10 the pin 72 rides along the peripheral edge 46 until it rounds overthe corner at the junction of the peripheral edge and the secondshoulder 52. After rounding over the junction with the second shoulderthe pin 72 actually assists in closing the blade 14, since the spring 78biases the pin 72 toward the shoulder 52 and thus urges the blade 14toward its closed position.

Turning now to FIGS. 6, 6a, 7 and 7a, when opening the blade 14, atransition at 88 in the curvature of the peripheral edge 46 also makesit possible to take advantage of the spring biased pin 72 acting on thetang portion 44 to assist in opening the blade, since the blade lockingsurface portion 89 of the peripheral edge 46 of the tang 44 extends atan angle inward from the arcuate portion of the peripheral edge.

FIG. 8 illustrates a blade 90 of another embodiment of the invention.The blade 90 is similar to the blade 14 in that it includes a bladeportion 92 having an upper edge 94, a lower edge 96, and a tang 98generally similar to the tang 44. However, the tang 98 also includes aramp 100. The purpose of ramp 100 is to allow the locking assembly 60 toassist in opening of the blade 90 from its closed position. Referringbriefly to FIG. 4, when the knob 64 is moved toward the second positionof the lock assembly 60 (in the direction of arrow 65) the pin 72 pushesagainst ramp 100, causing partial opening of the knife by cam action.This is desirable so that the knife can be opened with one hand.

Referring now to FIGS. 9-13, a multi-bladed tool 110 which is analternative embodiment of the present invention includes a handle 112 inthe form of a generally U-shaped channel, preferably of bent sheetsteel, with a plurality of tool blades 114, 116 and 118 mountedside-by-side on a blade pivot shaft 122 at one end 124 of the handle112. Each of the blades 114, 116 and 118 may be selected individually tobe moved between an extended open position such as that of thescrewdriver blade 114 shown in FIGS. 9, 10 and 11, and a closed positionas that of the screwdriver blade 114 as shown in FIG. 12.

The handle 112 includes a transversely extending back portion 126 havingan outer margin 144, and a pair of parallel side wall portions 128 and130 which extend parallel with each other and perpendicular to the backportion 126, thus defining a wide groove 132. The blade pivot shaft 122is mounted securely and immovably with respect to the side walls 128 and130, as by having each of its opposite ends 134 riveted or welded intoplace in a hole 136 defined in a respective one of the side walls. Eachof the blades 114, 116 and 118 includes a working portion 138 such asthat portion of the screwdriver blade 114 shown in FIG. 9 extendingoutwardly beyond the handle 112, and a tang portion 140. The tang 140 ofeach of the tool blades 114, 116 and 118 includes a respective bore thatfits snugly but rotatably about the blade pivot shaft 132. Each tang 140also includes an abutment shoulder 142 that rests against and issupported by the outer margin 144 of the back portion of the end 124 ofthe handle 112 when the respective tool blade is in the open position toestablish the proper location of the blade for use.

As with the previously-described knife 10, a pair of similar elongateopenings 150 are aligned with each other and extend through the sidewalls 128 and 130 of the handle 112. The elongate openings 150 aredefined in part by flat surfaces 151 located near the back 126 of thehandle 112. A blade locking pin 152, having a longitudinal axis 153,extends transversely of the handle 112 through both of the elongateopenings 150, with its opposite ends located adjacent the outer sides ofthe two side walls 128 and 130. A respective retainer 154, 156 such as arivet head or a small disc-shaped cap mated with the pin 152 by threads,is located on each end of the blade locking pin 152, and both retainersmay be gripped conveniently as release buttons by a person using thetool 110, to move the blade locking pin 152 longitudinally, with respectto both the handle 112 and the elongate openings 150 through the sidewalls 128 and 130, as indicated by the arrow 158. The blade locking pin152 includes an outer surface 160 parallel with its axis 153. For thesake of simplicity the central portion or body of blade locking pin 152,including the outer surface 160, is in the shape of a circular cylinder,but it will be appreciated that other shapes could also serve so long asthe blade locking pin 152 fits snugly but slidably in the elongateopenings 150.

The tang 140 of each tool blade 114, 116 and 118 includes a lockingsurface 162 oriented at a small angle 164 with respect to the interiorsurfaces 151 defining a part of the elongate openings 150 when therespective tool blade is in its open position. As with the lockingmechanism of the folding knife 10 the angle 164 should be between 7degrees and 14 degrees and is preferably 10 degrees. The locking surface162 is generally flat and merges into a convex arcuate peripheral edgesurface 166 acting as a cam along which the outer surface 160 of bladelocking pin 152 can slide during movement of a blade such as thescrewdriver 114 between its open position (FIG. 9) and its closedposition (FIG. 12). The blade locking pin 152 is shown in FIGS. 9 and 10in its first position, in which its outer surface 160 engages or is veryclose to the locking surface 162 of the tang 140 and approaches ashoulder 168 defined on the tang 140, while the blade locking pin issupported by the interior surfaces 151 of the elongate openings 150through the side walls 128 and 130.

On the opposite side of the tang 140 from the locking surface 162 is aclosed blade retaining surface 170 which is normally engaged by theouter surface 160 of the blade locking pin 152 when the blade 114 isclosed. As a mater of design choice or of production tolerances theremay be a very small clearance between the outer surface 160 and thelocking surface 162 or retaining surface 170 of either an open blade ora closed blade, allowing some small amount of movement. Each blade 114,116 and 118 also includes a shoulder 171 located on the tang 140,opposite the stop 142, to rest against the inner surface of the back 126of the handle to establish the proper closed position of the bladewithin the groove 132 defined between the side walls 128 and 130.

Two springs 172 are mounted, one on each side of the handle 112, to urgethe blade locking pin 152 toward its first position, yet allow the bladelocking pin to be retracted by the user of the tool when it is desiredto move a selected one of the tool blades 114, 116 and 118 between itsopen and closed positions. Each spring 172 is generally oxbow-shapedwith a respective loop 174 at each of its ends. Each spring 172 isattached to the respective side walls 128 or 130 of the handle by afastener 176 such as a screw or rivet extending through the respectiveloop 174 into the side wall, while the loop 174 at the opposite end ofeach spring 172 extends around the blade locking pin 152 near therespective end thereof, between the retainer 154 or 156 and therespective side wall of the handle 112.

At the opposite end 178 of the handle 112 a tang or handle stub 180 of apair of pliers is attached to the handle 112 in the same manner as arethe blades 114, 116 and 118. The handle stub 180 has the same profile asthe tang 140 and thus can similarly be locked in its extended or openposition with respect to the handle 112 for use of the pliers, as shownin FIG. 9. A second handle 112 (not shown) would be similarly attachedto the tang of the other pliers jaw so that the handles could be foldedtoward each other to enclose the pliers jaws or be extended and held inthe open position of each pliers jaw by the locking mechanism, for useof the pliers.

A folding knife 182, shown in FIGS. 14-17, is a further embodiment ofthe present invention and includes an elongate handle 184. The handle184 comprises a pair of liners 186, preferably of steel or titanium,which are similar to each other, each having an outer side 188. A spine190 that may be of metal or a suitable plastic is located between theliners 186, establishing a spacing between them to define a groove 192in which to receive a blade 194. The blade 194 is pivotally connectedwith one end 195 of the handle 184 by a pivot shaft 196, preferably inthe form of a tubular bolt having a flat side that fits in a mating hole197 defined in each of the liners 186 and extends rotatably through apivot hole 199 in the blade 194. The blade 194 includes a workingportion 198 having a blunt back 200 and a sharp edge 202. The blade 194also has a tang 204 and an abutment shoulder 206 where the back 200 isinterconnected with the tang 204.

A stop pin 208 extends transversely between the liners 186 and issecurely interconnected with them as by fitting tightly in holes definedin the liners 186 at the same end 195 of the handle, and the abutmentshoulder 206 rests snugly against the stop pin 208 when the blade 194 isin its open, extended, position for use.

The tang 204 includes a generally flat transverse locking surface 210which is located in generally the same position as the locking surface89 of the tang portion 44 of the knife 10 described above. The tang 204also includes an arcuate peripheral edge 212 that can act as a camsurface as described above in connection with the tang 44, and there isa shoulder 214 adjoining and directed inwardly from the arcuateperipheral edge 212, on the side of the working portion 198 nearer thesharp edge 202.

A pair of elongate openings 216, corresponding with the elongateopenings 74 of the knife 10, are defined in the liners 186 and arelocated opposite each other. A locking pin 218 extends through both ofthe elongate holes 216, thus extending transversely with respect to theelongate handle 184. The locking pin 218 has a retainer 220 at each ofits ends securely fastened in place, as by being formed integrally witha generally cylindrical body portion of the locking pin 218 which has anouter surface 221, or by being mated with the body of the locking pin218 by suitable threads or the like.

Each of the retainers 220 has a respective base surface 222 facinginwardly toward the outer side 188 of the respective one of the liners186, with the base surfaces 222 preferably spaced within a distance of0.003-0.008 inch from the outer sides 188. The retainers 220 extendradially outward about the body by a distance 223 of about 0.06 inch,for example, in order to keep the locking pin 218 oriented substantiallyperpendicular to the outer sides 188 of the liners 186. The retainers220 preferably are shaped to include grip surfaces 224 which can easilybe engaged securely by the thumb and forefinger of a person using theknife.

Each of the retainers 220 includes an annular groove 226. A pair ofsprings 228, 229 are mirror opposites of each other and have a generallyhorseshoe-like shape, each having a laterally inwardly directed endportion 230 or 231 and a small end loop portion 232. The laterallydirected end portions 230, 231 each fit into a spring-receiving hole 234in a respective one of the liners 186, while the end loops 232 fitaround the retainers 220 and are received in the grooves 226. When inplace, the springs 228 are bent inwardly so that they urge the lockingpin 218 toward the end of the handle 184 and thus toward the first, orlocking, position of the locking pin 218 with respect to the lockingsurface 210 of the tang 204, in the same fashion in which the springs172 urge the blade locking pin 152 toward its first, or locking,position with respect to the locking surface 166 of the tang 140described above.

A pair of outer plates 236 and 238, which may be of metal or adecorative material such as wood or plastic, are held in place closelyalongside the outer sides 188 of the liners 186, by fasteners such asscrews 240 and 242 at the rear end of the handle 184. The outer plates236 and 238 include countersunk shoulders 239 that are also engaged bythe heads 243 of the pivot shaft 196, which hold the outer plates 236and 238 tightly against the liners 186 at the first end 195 of thehandle and also are adjusted to provide enough tension to press theliners 186 against the lateral surfaces of the tang 204 to keep theblade 194 from being too loose in the groove 192 between the liners 186.

The outer plates 236 and 238 are mirror opposites of each other, andboth define respective spring cavities 244 which are also mirroropposites of each other. The spring cavities 244 provide clearance forthe springs 228 to flex and move with respect to the liners 186 as thelocking pin 218 moves.

Access openings 246 are defined through each of the outer plates 236 and238 to surround the retainers 220, which are thus countersunk within theopenings 246. The access openings 246 are large enough to provide forthe range of motion available for the locking pin 218 in the elongateopenings 216, so that the locking pin 218 can be moved against the forceof the springs 228 by engaging the grip surfaces 224 with one's thumband forefinger, to move the locking pin 218 away from its first positionand permit the blade 194 to be moved from its open position toward itsclosed position.

When the blade 194 is in its open position with the abutment shoulderresting against the stop pin 208 as shown in FIG. 15, there is an angle248 of preferably about 10 degrees between the locking surface 210 andan interior surface 249 of the elongate holes 216 against which thelocking pin 218 rests when the outer surface 221 of the locking pin 218is resting on the locking surface 210. Thus the locking pin 218 is urgedby the springs 228 into a narrow V-shaped space, to urge the blade 194to rotate about the pivot shaft 194 to urge the abutment shoulder 206snugly against the stop pin 208. The angle 248 is small enough so thatpressure against the back 200 of the blade 194 in the open positioncannot move the locking pin 218 out of engagement between the lockingsurface 210 and the interior surfaces 249 by cam action, and the lockingpin 218 thus securely retains the blade 194 in the open position.

As may be seen in FIG. 17, when the blade 194 is in its closed positionthe springs 228 urge the locking pin 218 against the shoulder 214. Asthe blade 194 is moved slightly from its fully closed position, theshoulder 214 of the blade 194 presses against the outer surface 221 ofthe locking pin 218 and moves it away from its first position. Uponfurther movement of the blade 194 in the same direction, indicated bythe arrow 250, the locking pin 218 is carried into contact with thearcuate peripheral edge 212 or cam surface of the tang 204, which itfollows until the blade 194 approaches its fully open position, at whichtime the springs 228 urge the locking pin 218 onto the locking surface210 to lock the blade 194 in its open position.

The terms and expressions which have been employed in the foregoingspecification are used therein as terms of description and not oflimitation, and there is no intention, in the use of such terms andexpressions, of excluding equivalents of the features shown anddescribed or portions thereof, it being recognized that the scope of theinvention is defined and limited only by the claims which follow.

1. A folding tool knife, comprising: (a) a handle having a pair ofopposite ends and including defined by a pair of elongate side wallsspaced apart from each other and defining a blade receiving groovetherebetween, each of said side walls defining one of a pair of elongateopenings located opposite each other, said handle including defined by apair of liners and an outer plate located outwardly alongside saidliner, each of said elongate openings are defined by said liners andextend therethrough, liners having an elongate liner opening extendingthrough said liners and located opposite each other and one of saidhandle further including a pair of outer plates of which one is locatedoutwardly alongside each of said liners, outer plates defines anelongate outer plate opening communicating with the elongate lineropening in the adjacent liner, and each of said outer plates defining arespective cavity adjacent one of said elongate liner openings and eachof said elongate liner openings communicating between said groove andthe respective cavity; (b) a tool knife blade pivotally attached to saidhandle proximate one of said ends and movable about a blade pivot axisextending transversely with respect to said side walls, between a closedposition and an open position of said blade, said blade having anelongate working portion and a tang, said elongate working portion beingreceived within said groove when said blade is in said closed positionand extending away from said handle when said blade is in said openposition, and said tang being located between said side walls when saidblade is in said open position; (c) said tang having a peripheral edgeincluding a locking surface portion thereof; (d) a blade locking pinextending transversely with respect to said handle and having a pair ofopposite end portions each extending through a respective one of saidelongate liner openings defined in said side walls liners, said bladelocking pin having an outer surface of which a portion is locatedbetween said side walls, and said blade locking pin being movablelongitudinally of said elongate liner openings between a first position,in which said outer surface engages said locking surface portion of saidtang when said blade is in said open position and thus locks said bladein said open position, and a second position in which said locking pinis spaced away from said locking surface portion of said tang, thusallowing said blade to move from said open position; and (e) a springdisposed between said handle and said locking pin, said spring locatedwithin said cavity defined between one of said liners and the one ofsaid outer plates located alongside said one of said liners, said springurging said locking pin toward said first position along a path definedby said elongate openings in said side walls.
 2. The folding tool ofclaim 1 wherein said spring is located within said cavity definedbetween one of said liners and the one of said outer plates locatedalongside said one of said liners.
 3. The folding tool knife of claim 1,including a lock assembly body member fixedly attached to said lockingpin, said lock assembly body member extending alongside one of saidliners and being movable along said one of said liners, thereby movingsaid blade locking pin between said first and second positions.
 4. Thefolding tool of claim 1, said locking pin including a retainer locatedat each of said opposite end portions thereof, each said retainerextending radially outward about said locking pin and including a basesurface located outwardly alongside a respective one of said liners andkeeping said locking pin oriented transversely with respect to saidhandle.
 5. The folding tool of claim 4, including a pair of saidsprings, each one of said pair having a first end interconnected with arespective one of said liners and an opposite end engaging a respectiveone of said retainers and thereby urging said locking pin toward saidfirst position.
 6. The folding tool of claim 1 wherein said handleincludes a pair of outer plates of which one is located outwardlyalongside each of said liners, each of said outer plates defining arespective cavity located adjacent one of said elongate openings, andeach of said outer plates defining an opening therethrough aligned withsaid one of said elongate openings and exposing an end of said lockingpin.
 7. The folding tool of claim 6 wherein said spring is located insaid cavity defined by one of said outer plates, between said one ofsaid pair of outer plates and the one of said liners located alongsidesaid one of said pair of outer plates.
 8. The folding tool knife ofclaim 1 wherein said locking pin is carried on a lock assembly bodymember extending longitudinally on said handle and located movablywithin one of said side walls.
 9. The folding tool knife of claim 8,including a latch operating arm attached to said lock assembly bodymember and projecting outwardly through an the elongate outer plateopening defined in said one of said side walls outer plates.
 10. Thefolding tool knife of claim 1 including a spine disposed between saidside walls and including an inner surface facing toward said lockingsurface portion of said tang and spaced apart from said peripheral edgeof said tang when said blade is in said open position.
 11. The foldingtool knife of claim 10 wherein said inner surface of said spine isaligned with both of said elongate liner openings and respectiveportions of said outer surface of said locking pin engage both saidinner surface of said spine and said locking surface portion of saidtang when said locking pin is in said first position.
 12. The foldingtool knife of claim 1 wherein said peripheral edge of said tang includesa ramp surface located so that said blade locking pin engages said rampand forces said blade from said closed position toward said openposition when said locking pin is moved from said first position towardsaid second position.
 13. The folding tool of claim 1, including a bladepivot shaft and plurality of blades all pivotally attached to saidhandle proximate said end thereof, each of said blades being movableseparately about said blade pivot shaft and each of said bladesincluding a tang having a respective locking surface portion.
 14. Thefolding tool of claim 13 wherein said handle includes a generallyU-shaped channel member including a handle back portion and a pair ofparallel side walls each defining one of said elongate openings, saidtool including a pair of said springs, each of said pair being attachedto a respective one of said side walls and acting upon said bladelocking pin proximate a respective one of said end portions thereof. 15.The folding tool of claim 14 wherein said locking pin has a respectiveretainer located at each of said opposite end portions thereof adjacentan outer face of respective one of said side walls.
 16. The folding toolof claim 13 wherein said tang of one of said plurality of bladesincludes a retainer surface, said blade locking pin being locatedclosely adjacent to said retainer surface when said one of said bladesis in its closed position and said blade locking pin is in said firstposition, said one of said plurality of blades thereby being kept insaid closed position until said blade locking pin is moved to saidsecond position.
 17. The folding tool knife of claim 1 wherein saidperipheral edge of said tang defines a cam against which said lockingpin is urged by said spring as said blade is moved between said openposition and said closed position.
 18. The folding tool of claim 1,including a pair of said handles and a pair of said tool blades, whereinsaid pair of tool blades are a pair of pliers jaws pivotallyinterconnected with each other.
 19. A folding knife, comprising: (a) ahandle having a body portion defining an elongate groove locatedtherein; (b) a blade pivotally attached to the body portion of thehandle at one end of the body portion, said blade being movable betweena closed position in which the blade is received within the groove ofthe handle and an open position in which the blade is extended away fromthe handle and exposed, said blade having a working portion whichextends away from the handle when the blade is in its open position anda tang portion which is substantially received within said elongategroove when the blade is in its open position, said tang portion havinga peripheral edge defining a cam; (c) a pin having acylindrically-shaped outer surface and a long axis extending in adirection generally transverse with respect to the direction of thehandle and blade, said pin being movable between a first position inwhich an outer surface of the pin engages the tang portion of blade forlocking the blade in its open position and a second position in whichthe pin is spaced away from the tang portion of the blade for allowingthe blade to move to its closed position, the outer surface of said pinriding upon the cam of the tang portion during movement of the blade toits open position when the pin is in its second position; (d) aresilient member biasing the pin to its first position; and (e) meansfor manually moving the pin to its second position from its firstposition.
 20. A tool having an elongate body, an implement, and animproved locking mechanism, wherein the body includes two opposedsidewalls and a connecting spine thereby forming a channel that ispartially bounded by the sidewalls and the spine, the implement ispivotally attached to the body and the implement is movable from a firstposition in which it is at least partially received in the body channeland a second position in which the implement is partially rotated out ofthe body channel for use, and the locking mechanism can hold theimplement in the second position, the improvement comprising: (a) a slotin each of said sidewalls, each slot defining an opening through arespective sidewall to the body channel; (b) the locking mechanismhaving a transverse member that extends transverse to the body, saidtransverse member having opposite ends extending through a respectiveone of said slots, said transverse member movable in said slots betweenan implement locking position and an implement unlocking position sothat when the implement is in the second position and the transversemember is in the locking position and pressure is applied to theimplement to urge it toward the first position, the transverse memberwedges between the sidewalls and the implement thereby preventing theimplement from moving to the first position.
 21. The tool of claim 20,wherein each sidewall includes an outer plate and a liner, and the slotsfurther define an opening in each liner.
 22. The tool of claim 20further including a bias member that urges the transverse member intothe implement locking position.
 23. The tool of claim 22, wherein thetransverse member is a pin that extends into the slots of each sidewall.24. The tool of claim 20, wherein the transverse member includes animplement engaging portion and a sidewall engaging portion that are ofunitary construction, and when pressure applied to said implement urgesthe implement to move from the second position to the first position,the implement bears against the implement engaging portion and thesidewall engaging portion bears against both sidewall slots therebyhindering the implement from moving to the first position.
 25. A foldingtool knife, comprising: a handle having first and second opposedsidewalls held in a spaced-apart arrangement to define an elongate slottherebetween, at least one said sidewalls having a cavity definedtherein facing said elongate slot and each of said sidewalls comprisingan outer plate and a liner alongside said outer plate, said cavityformed in an outer plate so that the cavity is located between the linerand the outer plate; an implement blade having a working portion and atang portion having a peripheral edge defining a cam and a shoulder atthe a junction of the cam and the working portion, said tang portionpivotally attached to one end of the handle and said implement blademovable between a closed position in which the implement blade is atleast partially received within the elongate slot and an open positionin which the implement blade is extended away from the handle; animplement blade locking member movable between a first position in whichthe member engages said tang to lock said implement blade in said openposition and a second position in which the member disengages said tangso that said implement blade may be moved into said closed position; atleast one resilient spring member for urging said implement bladelocking member to the first position, said resilient member received insaid cavity and having a first end interconnected to said implementblade locking member and a second end interconnected to a sidewall. 26.The folding tool of claim 25 wherein both sidewalls have a cavity formedtherein facing said elongate slot, and a pair of resilient springmembers, one in each cavity, each having a first end interconnected tosaid implement locking member and a second end interconnected to asidewall.
 27. The folding tool knife of claim 25 in which the at leastone resilient spring member comprises a U-shaped member .
 28. Thefolding tool knife of claim 27 in which the first end of the U-shapedmember includes defines a loop that interconnects with said implementblade locking member.
 29. A folding tool knife, comprising: a handlehaving first and second opposed sidewalls, each sidewall defined by aninner liner and an outer plate located outwardly alongside each liner,and each sidewall defining a slot, said sidewalls held in a spaced-apartarrangement to define an elongate slot blade receiving groovetherebetween, and each of said outer plates defining a cavity adjacent arespective one of said elongate openings slots; an implement bladehaving a working portion and a tang portion having a peripheral edgedefining a cam and a shoulder at the a junction of the cam and theworking portion, said tang portion pivotally attached to one end of thehandle and said implement blade movable between a closed position inwhich the implement blade is at least partially received within theelongate slot blade receiving groove and an open position in which theimplement blade is extended away from the handle; an implement bladelocking member extending through said slots and movable between a firstposition in which the member engages said tang to lock said implementblade in said open position and a second position in which the memberdisengages said tang so that said implement blade may be moved into saidclosed position; a spring located in each cavity between the outer plateand the respective inner liner, each spring having a first endinterconnected to said implement blade locking member and a second endinterconnected to an inner plate.
 30. A folding tool knife, comprising:a handle comprising first and second sidewalls, each sidewall defined byan inner liner and an outer plate, and each sidewall having an openingextending through said inner liner and outer plate, said sidewalls heldin a spaced-apart arrangement to define a slot therebetween and each ofsaid sidewalls outer plates having a cavity formed therein; an implementblade having a working portion and a tang portion, said implement bladepivotally attached to the handle and movable between an open positionand a closed position; a lock member having opposite ends extendingthrough said openings in said sidewalls; a substantially U-shaped springin each cavity, each spring having a first end interconnected to saidlock member and a second end interconnected to an inner plate.
 31. Afolding knife, comprising: a handle having a substantially planar firstsidewall, including a first inner liner and a first t outer plate and afirst opening extending through said inner liner and outer plate, saidfirst sidewall outer plate having a first cavity formed therein; a bladepivotally attached to the handle and movable between an open positionand a closed position; a lock member extending through said firstopening in said first sidewall in a direction transverse to said firstsidewall; a first spring in said first cavity, said first spring havinga U-shaped portion and a first end associated with said lock member anda second end anchored to said sidewall.
 32. The folding knife accordingto claim 31 including a second sidewall with a second opening, saidsecond sidewall parallel to said first sidewall and defining a slottherebetween.
 33. The folding knife according to claim 32 wherein saidsecond sidewall includes a second cavity with a second spring.
 34. Thefolding knife according to claim 33 wherein said locking member extendsthrough said second opening in a direction transverse to said secondsidewall.
 35. The folding knife according to claim 31 wherein saidlocking member is movable in a plane parallel to the plane of the firstsidewall.
 36. The folding knife according to claim 31 wherein said firstspring includes an S-shaped portion.
 37. The folding knife according toclaim 31 wherein said first spring is moveable in a plane parallel tothe plane of the first sidewall.
 38. The folding knife according toclaim 31 wherein said blade has a tang portion and said locking memberhas a curved outer surface engaging the tang portion of the blade. 39.The folding knife according to claim 38 wherein said tang portiondefines a cam and wherein said curved outer surface rides on said cam.40. The folding knife according to claim 31 wherein said locking memberextends through said first cavity.
 41. The folding knife according toclaim 31 wherein a portion of said first cavity is coextensive with saidfirst opening.
 42. The folding knife according to claim 41 wherein saidfirst spring engages said locking member in a portion of said firstcavity that is coextensive with said first opening.
 43. A knife havingan elongate body, a blade, and an improved locking mechanism, whereinthe body includes two opposed sidewalls held in a spaced-apartarrangement thereby forming a channel therebetween that is partiallybounded by the sidewalls , the blade is pivotally attached to the bodyand is movable from a first position in which it is at least partiallyreceived in the body channel and a second position in which the blade ispartially rotated out of the body channel for use, and the lockingmechanism can hold the blade in the second position, the improvementcomprising: (a) the locking mechanism having a transverse member thatspans the sidewalls so that the transverse member rides in elongateopenings in the sidewalls so that when the blade is in the secondposition and urged toward said first position, said transverse memberwedges between the sidewalls and the blade thereby preventing the bladefrom moving to the first position, wherein each sidewall comprises aninner liner and an outer plate, the elongate openings extend throughsaid inner liner and outer plate of each sidewall, and each of saidsidewalls outer plates has a recess formed therein, and a springreceived in each recess, each spring having a first end associated withsaid transverse member and a second end anchored to an inner linersidewall .
 44. A folding knife comprising: a handle having first andsecond opposed sidewalls, each sidewall defined by an inner liner and anouter plate located outwardly alongside each liner, and each sidewalldefining and elongate opening, said sidewalls held in a spaced-apartarrangement to define an elongate slot therebetween, and each of saidouter plates defining a cavity adjacent a respective one of saidelongate openings; a blade having a tang end pivotally attached to oneend of the handle and movable between a closed position in which theblade is at least partially received in the elongate slot and an openposition in which the blade is extending away from the handle; a bladelocking member having opposed ends extending through said slots elongateopenings and movable between a first position in which the membercontacts said tang end to lock said blade in said open position and asecond position in which the blade may be moved into said closedposition; a spring located in each cavity between the outer plate andthe respective inner liner, each spring having a first end associatedwith said blade locking member and a second end associated with saidsidewall inner liner.
 45. A lock mechanism for a folding knife,comprising: a handle comprising first and second sidewalls, eachsidewall defined by an inner liner and an outer plate, and each sidewallhaving an opening extending through said inner liner and outer plate,said sidewalls held in a spaced-apart arrangement to define a slottherebetween and each of said outer plates defining a cavity formedtherein adjacent said inner liners; a blade pivotally attached to thehandle and movable between an open position and a closed position; alock member having opposite ends extending through said openings in saidsidewalls; a spring confined in each cavity, each spring having a firstend engaging said lock member and a second end anchored to said sidewallinner liner.
 46. The lock mechanism according to claim 45 wherein eachspring defines a U-shaped portion .
 47. The lock mechanism according toclaim 45 wherein each spring defined an S-shaped portion.
 48. A lock fora folding knife, comprising: a handle comprising first and secondsidewalls, each sidewall defined by an inner liner and an outer plate,and each sidewall having an opening extending through said inner linerand outer plate, said sidewalls held in a spaced-apart arrangement todefine a slot therebetween and each of said sidewalls outer plateshaving a cavity formed therein; a blade pivotally attached to the handleand movable between an open position and a closed position; a lockmember having opposite ends extending through said openings in saidsidewalls so as to be exposed, and the lock member movable between afirst position wherein the lock member locks the blade in the openposition, and a second position wherein the lock member permits theblade to be moved to the closed position; a wire spring in each cavity,each wire spring having a first end engaging to said lock member to urgethe lock member into the first position.
 49. The lock mechanismaccording to claim 48 wherein the lock member must be moved to thesecond position against the force of the wire springs to move the bladeinto the closed position.
 50. The lock mechanism according to claim 49wherein each spring defines a U-shaped portion .
 51. The lock mechanismaccording to claim 50 wherein one end of each U-shaped spring isconnected to the lock member and the opposite end of each U-shapedspring is connected to an inner liner.
 52. The lock mechanism accordingto claim 48 wherein said wire spring has a second fixed end and thefirst end is a movable end, said spring lies within a plane parallel tothe plane of said sidewall and said movable end moves in said plane.